Chinoperla sila, Sivec & Stark, 2010

Sivec, Ignac & Stark, Bill P., 2010, Five New Species Of Chinoperla Zwick (Plecoptera: Perlidae) From Vietnam And Thailand, Illiesia 6 (8), pp. 62-74 : 67-68

Chinoperla sila sp. n.

( Figs. 19-25 )

Material examined. Holotype ♂, 15♂ and 6♀ paratypes from Tam Dao , Vietnam, 800-1100 m, 19 May-13 June 1995, H. Malicky ( PMSL).

Adult habitus. Biocellate. Head with dark brown pigment over most of dorsum but interrupted by pale M-line and clypeus. Pronotum pale brown with darker rugosities clustered near midline and center of disk. Wings tinted brown except for narrow pale costal and apical band. Legs banded with narrow brown band on apex of femur and base of tibiae.

Male. Forewing length 9 mm. Median process of tergum 9 more or less circular and distinctly rugose. Finger like hemitergal processes short, ca. twice as long as basal width ( Fig. 22 ). Aedeagal tube poorly sclerotized and bearing a pair of sparse setal patches basolaterally ( Figs. 23-24 ); sac with a dorsal and smaller ventral membranous lobe and bearing a long slender terminal spine; basoventral margin of sac armed with sparse patch of small spines.

Female. Forewing length 10 mm. Subgenital plate unproduced but posterior margin of sternum 8 bearing a shallow, median U-shaped notch ( Fig. 25 ). Egg. Length ca. 0.39 mm, width ca. 0.22 mm. Tear drop shaped with short narrow collar and stalked anchor ( Fig. 19 ). Chorionic surface finely punctate throughout; collar surface and adjacent egg body with an irregular pattern of meshwork formed by anastamosing low ridges ( Fig. 20 ). Micropylar orifices slender, surrounded by small area of smooth chorion ( Fig. 21 ).

Larva. Unknown.

Etymology. The species name, used as a noun in apposition, honors the Si La people of northern Vietnam.

Diagnosis. This is another species whose aedeagus is similar to that of C. unidentata in having a single, long, slender apical spine ( Fig. 23 ). It can be distinguished from C. gorohovi and C. unidentata by the somewhat circular and rugose process of tergum 9 ( Fig. 22 ), and by the narrow pale margin of the wing tips.

Figures

Figs. 16-21. Chinoperla eggs. C. rhododendrona (16-18) 16. Egg. 17. Egg collar. 18. Micropyle and equatorial chorionic detail. Chinoperla sila (19-21). 19. Egg. 20. Egg collar and anchor. 21. Micropyles and polar chorionic detail.

Figs. 22-25. Chinoperla sila. 22. Male terminalia. 23. Aedeagus lateral. 24. Aedeagus dorsal. 25. Female terminalia.